Clocks

AP7200 has four oscillator inputs in addition to the internal RC oscillator.

OSC0 is the suggested the main clock and connected to a 20MHz x-tall on STK1005. This is usually feed to the PLL to achieve a 200MHz main clock.

OSC1 is typically attached to a x-tall suited for UART baud generation. On STK1005 this input is a socket.

OSC2 is used to get the 480 MHZ clock required for USB. A 12MHz x-tall is fitted on STK1005

Finally there is a 32Khz x-tall connected to the real time clock.